This invention relates to a (2-chloro-3-oxo-1-alkenyl)bicyclo[3.3.0]octene derivative and a process for preparing the same. This invention is to provide a novel compound available for a synthetic intermediate of prostacyclins and a process for preparing the same.
In the German Offenlegungsschrift No. 25 39 116 specification, there are disclosed a prostaglandin intermediate represented by the following formula: ##STR4## wherein R' represents a substituted or unsubstituted alkyl group, R" represents a protective group for a hydroxy group and X represents a chlorine atom or iodine atom, and a process for preparing said intermediate by reacting an aldehyde represented by the formula: ##STR5## wherein R" has the same meaning as defined above, with a compound represented by the formula: ##STR6## wherein R' and X have the same meanings as defined above, and R'" represents an alkyl group. Further, in the specification of Japanese Provisional Patent Publication No. 21642/1984, there is disclosed that an intermediate of the prostacyclin compound represented by the formula: ##STR7## can be prepared by reacting an aldehyde represented by the formula: ##STR8## with 3-oxophosphonate represented by the formula: ##STR9## in the presence of a base and N-bromosuccinimide. However, there is no literature concerning a (2-chloro-3- oxo-1-alkenyl)bicyclo[3.3.0]octene derivative represented by the general formula (I): wherein R.sup.1, R.sup.2 and R.sup.3 have the meanings as defined below, and a process for preparing the same.